SMA is a
muscular disease passed on genetically to children by their parents.
You can not "catch" SMA by being around someone who has
it. It is a "Recessive" genetic disease, meaning that BOTH
parents must carry a copy of the recessive SMA gene. There is only a
25% chance each pregnancy of the child having SMA and a 75% chance each
pregnancy that the child will be healthy. One out of 40 people is a
carrier of this recessive gene. The brain is not affected, and
they have been tested to have at least average to above average
intelligence. Please do not make the mistake of treating them as
mentally impaired!! Their bodies may not be perfect, but their minds
are, so be sure to treat them that way! SMA affects a child's
muscular development, and the severity depends on what 'type' of SMA the
child has. There are four "Types" of SMA, Type 1,2,3 &
4. The earlier the symptoms are noticed, the more severe the
type of SMA. Type 1 is the most severe, affecting children while
still in the womb or shortly after birth. Type 4 is the least
severe, affecting adults.

Type
1children
are diagnosed usually before 6 months of age, more often before 3 months
of age. Symptoms may even start in the womb. Many mothers
later recall the baby not moving as much the last month or so of
pregnancy. They are not able to hold up their heads, roll over,
crawl, sit up without support, or walk. All of their muscles are
extremely weak, with the weakest muscles being the legs, upper arms, and
neck. Their chest may appear concave, or very skinny at the top,
with a big belly. Bell-shaped. SMA affects all muscle systems
as well including sucking, swallowing, digesting food, and
excretion. Constipation is a common problem as is being able to
control excessive drooling (secretions), and getting proper nutrition and
calories for proper weight gain. A common cold can easily turn into
pneumonia which is what usually takes the lives of these children, along
with "respiratory failure" or when they no longer have the lung
or chest muscles to be able to breathe on their own. Two major
decisions must be made with Type I children...whether or not to insert a
feeding tube to prevent pneumonia and prevent starvation when they have
lost their ability to suck or swallow; and whether or not to put them on a
ventilator or other breathing machine when they experience respiratory
failure. Current statistics show that the average lifespan of a
child with SMA Type I, not put on permanent ventilation or "life
support", is only 8 months of age, with 80% dying by the age of one,
and the majority of the rest dying by age 2. HOWEVER, these
statistics are not a hard and fast rule. Each child is affected so
differently by SMA that they do not all follow the same path or
progression. Also, as more is learned about SMA, the lifespan of a
Type 1 child can be lengthened depending on the severity of the symptoms
for each particular child. Last but not least, the line between each
Type of SMA is not clearly defined, and it is common for a child to
exhibit patterns of two types, thus confusing the issue of "life
expectancy" for that child.

Type I
children most often have very little leg movement, very little upper arm
movement. Many times their hands remain fisted and their hands/wrists are
turned the "wrong" way. The physical characteristics that
often "gives them away" to having SMA is a bell shaped body,
legs that stay in the "frog" position, moving the arms from the
elbows down only, and the head tilted to the side because of lack of neck
muscles. They often have bright, expressive faces and
eyes.

Type
2 children
are diagnosed before 2 years of age, usually more like 15 months.
These children are usually able to be in a sitting position without
support, but often can not get there by themselves. They can
sometimes crawl with bracing and therapy, and on occasion may stand with
braces. Feeding and swallowing problems are not common in Type 2
children, though they are still possible. They will usually never
walk. The lifespan of a Type 2
child varies so widely, there isn't one! They could pass away at an
early age or they could live well into adulthood. As with all forms
of SMA, weakness increases over time.

Type
3 children
are diagnosed between 18 months of age and early adolescence. In the
beginning these
children are able to stand and walk but usually have difficulty doing
so. They typically have a normal lifespan; however, as with all
forms of SMA, weakness gets progressively worse and they usually will be
wheelchair bound.

Type
4SMA is
an
adult SMA, with symptoms beginning around age 35. They also
usually have a normal lifespan; though, as with all forms of SMA, weakness
gets progressively worse.